Automatic QA of BSMDE minB spectra. 

Content

1. example of good spectra (fig 0)
2. QA cuts definition (table 1) + spectra (figs 1-7)
3. Result:
   1. # of bad strips per module. BSMDE modules 10,31,68  are damaged above  50%+. (modules 16-30 served by crate 4 were not QAed). 
   2. eta-phi distributions of: slopes, slope error (fig 9) , pedestal, pedestal (fig 10) width _after_ QA
   3. sample of good and bad plots from every module, including modules 16-30 (PDF at the end)

The automatic  procedure doing QA of  spectra was set up in order to preserve only good looking spectra as shown in the fig 0 below. 

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Fig 0   Good spectra for random strips in module=2. X-axis shows pedestal residua. It is shown to set a scale for the bad strips shown below. 

 

INPUT: 3M d-AU events from day ~336 of 2007.

All spectra were pedestals subtracted, using one value per strip, CAPS=123,124,125 were excluded. Below I'll use term 'ped' instead of more accurate pedestal residuum.

Method: fit slopes to ADC =ped+40,ped+90 or 5*sig(ped) if too low.

The spectra,  fits of pedestal residuum, and slopes were QAed.

QA method was set up as sequential series of cuts, upon failure later cuts were not checked.

Note, BSMD rate 4 had old resistors in day 366 of 2007 and was excluded from this analysis.
This reduces # of strips from 18,000 to 15,750 . 

 

Table 1 Definition of QA cuts

cut#	cut code	description	# of discarded strips	figure
1	1	at least 10,000 entries in the MPV bin	4	-
2	2	MPV position within +/-5 ADC channels	57	Fig 1
3	4	sig(ped) of gauss fit in [1.6,8] ADC ch	335	Fig 2
4	8	position of mean gauss within +/- 4 ADC	11	Fig 3
5	16	yield from [ped+40,ped+90] out of range	441	Fig 4
6	32	chi2/dof from slop fit in [0.6,2.5]	62	Fig 5
7	64	slopeError/slop >16%	4	Fig 6
8	128	slop within [-0.015, -0.05]	23	Fig 7
-	sum	out of processed 15,750 strips discarded	937 ==> 5.9%

 

 

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Fig 1 Example of strips failing QA cut #2, MPV position out of range , random strip selection

 

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Fig 2a Distribution of width of pedestal vs. eta-bin

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Fig 2b Example of strips failing QA cut #3, width of pedestal out of range , random strip selection

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Fig 3a Distribution of pedestal position vs. eta-bin

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Fig 3b Example of strips failing QA cut #4, pedestal position out of range , random strip selection

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Fig 4a Distribution of yield from the slope fit range vs. eta-bin

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Fig 4b Example of strips failing QA cut #5, yield from the slope fit range out of range , random strip selection

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Fig 5a Distribution of chi2/DOF from the slope fit vs. eta-bin

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Fig 5b Example of strips failing QA cut #6, chi2/DOF from the slope fit out of range , random strip selection

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Fig 6a Distribution of err/slope vs. eta-bin

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Fig 6b Example of strips failing QA cut #7, err/slope out of range , random strip selection

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Fig 7a Distribution of slope vs. eta-bin

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Fig 7b Example of strips failing QA cut #8, slope out of range , random strip selection

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Results

Fig 8a Distribution of # of bad strips per module. 

BSMDE modules 10,31,68  are damaged above  50%+. Ymax was set to 150, i.e. to the # of eat strips per module. Modules 16-30 served by crate 4 were not QAed. 

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Fig 8b 2D Distribution of # of bad strips indexed by eta & phi strip location. Z-scale denotes error code from the 2nd column from table 1.

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Fig 9 2D Distribution of slope indexed by eta & phi strip location.
TOP: slopes. There is room for gain improvement in the offline analysis. At fixed eta (vertical line) there should be no color variation.
BOTTOM error of slope/slope.

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Fig 10 2D Distribution of pedestal and pedestal width indexed by eta & phi strip location.
TOP: pedestal
BOTTOM: pedestal width.